U.S. Pat. Nos. 5,005,375 and 5,080,132, both assigned to the assignee hereof, disclose systems for servicing refrigeration equipment, such as air conditioning and heat pump equipment, by recovering refrigerant from such equipment, purifying the recovered refrigerant for removal of water or other contaminants, and/or charging the refrigeration equipment under service using stored or purified refrigerant. The systems disclosed in the noted patents feature self-sealing couplings adapted for mating engagement with externally threaded fittings of standard configuration on the equipment under service to facilitate interconnection with the service systems while substantially reducing likelihood of loss of refrigerant to the atmosphere, as well as any requirement for evacuating the interconnection hoses prior to use of the service systems.
The self-sealing couplings disclosed in the above-noted patents include an adapter having an internal bore or passage and a poppet urged by a spring toward the open end of the passage for engagement with an equipment service fitting when the adapter is received over the fitting. Either the adapter or the poppet carries a sealing ring for engagement with the opposing element under force of the spring to seal the passage when the coupling is not fastened to a fitting. A coupling element is movably mounted on the adapter for engagement with external threads on the service fitting releasably to fasten the coupling to the fitting while opening the poppet valve within the passage. The coupling element may comprise a coupler nut having internal threads for engagement with external threads on the fitting, or a quick-disconnect coupler with cam-operated sections for engaging the external threads on the fitting.
A general object of the present invention is to provide an improved coupling of the type disclosed in the noted patents in which the poppet is self-centering within the adapter passage, in which opening of the poppet yields more rapid flow of refrigerant through the coupling for enhanced efficiency of service, and/or that obtains improved sealing between the adapter on the one hand and the service fitting and poppet on the other.